title: Spatial and temporal assessment of pollen- and seed-mediated gene flow from genetically engineered plum Prunus domestica.
abstract: Pollen flow from a 0.46 ha plot of genetically engineered (GE) Prunus domestica located in West Virginia, USA was evaluated from 2000-2010. Sentinel plum trees were planted at distances ranging from 132 to 854 m from the center of the GE orchard. Plots of mixed plum varieties and seedlings were located at 384, 484 and 998 m from the GE plot. Bee hives (Apis mellifera) were dispersed between the GE plum plot and the pollen flow monitoring sites. Pollen-mediated gene flow from out of the GE plum plot to non-GE plums under the study conditions was low, only occurring at all in 4 of 11 years and then in only 0.31% of the 12,116 seeds analyzed. When it occurred, gene flow, calculated as the number of GUS positive embryos/total embryos sampled, ranged from 0.215% at 132 m from the center of the GE plum plot (28 m from the nearest GE plum tree) to 0.033-0.017% at longer distances (384-998 m). Based on the percentage of GUS positive seeds per individual sampled tree the range was 0.4% to 12%. Within the GE field plot, gene flow ranged from 4.9 to 39%. Gene flow was related to distance and environmental conditions. A single year sample from a sentinel plot 132 m from the center of the GE plot accounted for 65% of the total 11-year gene flow. Spatial modeling indicated that gene flow dramatically decreased at distances over 400 m from the GE plot. Air temperature and rainfall were, respectively, positively and negatively correlated with gene flow, reflecting the effects of weather conditions on insect pollinator activity. Seed-mediated gene flow was not detected. These results support the feasibility of coexistence of GE and non-GE plum orchards.
authors.affiliation: U.S. Dept. of Agriculture, Appalachian Fruit Research Station, Kearneysville, West Virginia, United States of America.
authors.forename: Ralph
authors.initials: R
authors.lastname: Scorza
authors.forename: Alissa B
authors.initials: AB
authors.lastname: Kriss
authors.forename: Ann M
authors.initials: AM
authors.lastname: Callahan
authors.forename: Kevin
authors.initials: K
authors.lastname: Webb
authors.forename: Mark
authors.initials: M
authors.lastname: Demuth
authors.forename: Tim
authors.initials: T
authors.lastname: Gottwald
mesh_terms: D000818:Animals; D051456:Gene Flow; D005818:Genetic Engineering; D011058:Pollen / Q000502:physiology*; D054817:Pollination; D027861:Prunus / Q000235:genetics* / Q000502:physiology; D012639:Seeds / Q000502:physiology*; D062211:Spatio-Temporal Analysis; D019076:Transgenes / Q000235:genetics; D014887:Weather